Gold-Bearing Lodes in California.- — Hershey. 93 
when a distinct quartz vein is present, if it is gold-bearing, 
there has invariably been faulting along the fissure. I have yet 
to see a single valuable gold mine in northwestern California 
("pocket" deposits excepted) which is not so associated with a 
fault. The seams of schist and crushed country-rock repre- 
senting these faults, may be traced from the summit to the base 
of the mountains, demonstrating that they are not merely a 
local development, but may be depended on to go down to a 
great depth in the strata. Hence, it is certain that the so-called 
"ledges" may be depended on to continue down below a work- 
able distance of the surface, and the question of the permanen- 
cy of the mines narrows itself to one of determining whether 
these mineral seams are gold-bearing to an equal depth. 
3. The zones of crushed rock along the fault-planes, con- 
stituted lines of weakness in the strata, characterized by an 
open, porous texture, along which heated, mineral-bearing so- 
lutions ascended from a great depth, formed the cjuartz veins 
and mineralized the talcose schists and crushed rock. The pe- 
culiar modification of the rocks which these heated waters ac- 
complished is only found in connection with the faults, imply- 
ing that the mineral-bearing solutions only entered those 
breaks in the strata which descend to great depth. This is 
strong evidence that the gold was derived from below. 
4. The country-rock of the metamorphic series, aside from 
the crushed zones, is practically barren of gold, and the pre- 
cious metal could not have been derived by lateral secretion 
from the walls of the veins. Outside of the so-called "ledges" 
or crushed belts of country-rock, the strata are unleached and 
present no evidence of the mineral-bearing solutions having 
penetrated them. 
In short, the weight of evidence tends strongly to support 
the hypothesis that the gold was derived from a great depth, 
and brought up in solution by hot w^aters circulating only 
along the faulted fissures or porous belts. 
5. The presence of consideral^le (|uantitics of gold within 
the body of certain dike recks, suggests that it was original in 
these intrusives, and supi)licd to the veins by leaching from the 
dikes. In the case of the large white granite-porphyry dike in 
the Lawrence fault, it is only gold-bearing when accompanied 
bv the schistose bands indicating more recent faulting, and I 
